Role of endothelial selectins in wound repair

P- and E-selectins are adhesion molecules expressed on activated endothelium and platelets at sites of vascular injury and inflammation. The selectins are important for leukocyte recruitment. Because little is known about the role of selectins in wound healing, we studied cutaneous wound repair of full-thickness excisional skin wounds in mice lacking P-selectin, E-selectin, or both of these selectins. The absence of either selectin alone had no notable effect on healing, and the only deficit observed was a delay in early neutrophil extravasation in the P-selectin-deficient mice. Mice deficient in both P- and E-selectins had markedly reduced recruitment of inflammatory cells and impaired closure of the wounds. Wound sections, studied up to 3 days after wounding, showed significant impairment of neutrophil influx. Macrophage numbers were also reduced in the double mutants at 3 and 7 days after wounding as compared with wild-type mice. Additionally, a wider epithelial gap in the wounds of the P- and E-selectin- double-deficient mice 3 days after wounding indicated delayed keratinocyte migration. These results demonstrate an important combined role for P- and E-selectins in processes leading to wound healing.